The present invention relates to mechanical locking devices for positively clamping and holding a tensioned rope in a desired position. Although such devices are useful in a variety of applications, one particularly important use of such devices is in holding ropes used in stage theatres which raise and lower a plurality of different sets into and out of operative position on the theatre stage. Such sets are often quite heavy, yet are usually moved by hand and therefore hand operable quick release and locking devices are required to safely hold the tensioned ropes in position.
The locking devices which have reliably performed for years generally consist of a pair of opposed locking dogs between which the rope is clamped. A pivotally mounted handle provided with a camming surface is operatively engaged in sliding metal to metal contact with one of two pivotally mounted opposed locking dogs as the clamping device is actuated. The metal to metal contact between the camming surfaces on the handle and dog has been found to cause rapid wear of the handle or of the dog, or both with consequent increase in the possibility of slippage of the clamped rope and danger to personnel in the area of the theatre sets.
It is therefore the object of the present invention to provide a rope locking device which has easily replaceable parts and which is less difficult to move into and out of operative clamping position than the prior art arrangements.